Gorillas, like humans, appreciate a little positive reinforcement from their caregivers every once and a while. Dr. Ron Cohn has been raising Koko since she was 1 year old, with Dr. Penny Patterson, and is thus the only father figure Koko has ever known.
They have become very good friends over the years, which explains why Koko lets Ron take so many wonderful photos of her – except for this photo, which was of course taken by Dr. Patterson.
